silccore: packet injection and stream wrap improvements
[silc.git] / lib / silccore / silcpacket.h
index 4cc2b44285d2bd37bfe1c0acb751cb1ce1a0e1da..497a68a6812ddba3d835f324b2aed5baddffd59b 100644 (file)
@@ -4,7 +4,7 @@
 
   Author: Pekka Riikonen <priikone@silcnet.org>
 
-  Copyright (C) 1997 - 2007 Pekka Riikonen
+  Copyright (C) 1997 - 2014 Pekka Riikonen
 
   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
@@ -34,8 +34,6 @@
 #ifndef SILCPACKET_H
 #define SILCPACKET_H
 
-/* XXX many of these could go to silcpacket_i.h */
-
 /* Maximum packet length */
 #define SILC_PACKET_MAX_LEN 0xffff
 
@@ -117,7 +115,7 @@ typedef SilcUInt8 SilcPacketFlags;
 #define SILC_PACKET_FLAG_ACK              0x10    /* Acknowledge packet */
 
 /* Impelemntation specific flags */
-#define SILC_PACKET_FLAG_LONG_PAD         0x12    /* Use maximum padding */
+#define SILC_PACKET_FLAG_LONG_PAD         0x20    /* Use maximum padding */
 /***/
 
 /****s* silccore/SilcPacketAPI/SilcPacketEngine
@@ -198,6 +196,9 @@ typedef struct SilcPacketStruct {
  *    from the actual stream.  It can retrieve the underlaying stream from
  *    the packet stream by calling silc_packet_stream_get_stream function.
  *
+ *    You may retrieve string version of the SilcPacketError by calling
+ *    silc_packet_error_string.
+ *
  * SOURCE
  */
 typedef enum {
@@ -360,7 +361,7 @@ typedef struct {
  ***/
 SilcPacketEngine
 silc_packet_engine_start(SilcRng rng, SilcBool router,
-                        SilcPacketCallbacks *callbacks,
+                        const SilcPacketCallbacks *callbacks,
                         void *callback_context);
 
 /****f* silccore/SilcPacketAPI/silc_packet_engine_stop
@@ -377,6 +378,52 @@ silc_packet_engine_start(SilcRng rng, SilcBool router,
  ***/
 void silc_packet_engine_stop(SilcPacketEngine engine);
 
+/****f* silccore/SilcPacketAPI/silc_packet_error_string
+ *
+ * SYNOPSIS
+ *
+ *    const char *silc_packet_error_string(SilcPacketError error);
+ *
+ * DESCRIPTION
+ *
+ *    Return the packet error as string.
+ *
+ ***/
+const char *silc_packet_error_string(SilcPacketError error);
+
+/****f* silccore/SilcPacketAPI/silc_packet_engine_get_streams
+ *
+ * SYNOPSIS
+ *
+ *    SilcDList silc_packet_engine_get_streams(SilcPacketEngine engine);
+ *
+ * DESCRIPTION
+ *
+ *    Returns list of packet streams added to the packet engine.  The caller
+ *    must free the list with silc_packet_engine_free_streams_list.
+ *
+ * NOTES
+ *
+ *    This function may also return disconnected and destroyed streams.  The
+ *    caller should use silc_packet_stream_is_valid to check if the stream
+ *    is valid.
+ *
+ ***/
+SilcDList silc_packet_engine_get_streams(SilcPacketEngine engine);
+
+/****f* silccore/SilcPacketAPI/silc_packet_engine_free_streams_list
+ *
+ * SYNOPSIS
+ *
+ *    void silc_packet_engine_free_streams_list(SilcDList streams);
+ *
+ * DESCRIPTION
+ *
+ *    Free's the streams list returned by silc_packet_engine_get_streams.
+ *
+ ***/
+void silc_packet_engine_free_streams_list(SilcDList streams);
+
 /****f* silccore/SilcPacketAPI/silc_packet_stream_create
  *
  * SYNOPSIS
@@ -392,6 +439,10 @@ void silc_packet_engine_stop(SilcPacketEngine engine);
  *    stream.  After this function returns, packets can immediately be
  *    sent to and received from the stream.
  *
+ *    The `stream' will be owned by the packet stream and will be closed
+ *    and destroyed when the packet stream is destroyed.  If the packet
+ *    stream creation fails the `stream' is left intact.
+ *
  * NOTES
  *
  *    SilcPacketStream cannot be used with silc_stream_* routines (such as
@@ -460,6 +511,24 @@ SilcPacketStream silc_packet_stream_add_remote(SilcPacketStream stream,
                                               SilcUInt16 remote_port,
                                               SilcPacket packet);
 
+/****f* silccore/SilcPacketAPI/silc_packet_stream_inject
+ *
+ * SYNOPSIS
+ *
+ * SilcBool silc_packet_stream_inject(SilcPacketStream stream,
+ *                                    SilcPacket packet);
+ *
+ * DESCRIPTION
+ *
+ *    This function can be used to inject the `packet' to the given
+ *    packet `stream'.  The packet will appear in the packet stream's
+ *    packet handler(s).  If this returns FALSE the packet was not
+ *    injected.
+ *
+ ***/
+SilcBool silc_packet_stream_inject(SilcPacketStream stream,
+                                  SilcPacket packet);
+
 /****f* silccore/SilcPacketAPI/silc_packet_stream_destroy
  *
  * SYNOPSIS
@@ -474,6 +543,20 @@ SilcPacketStream silc_packet_stream_add_remote(SilcPacketStream stream,
  ***/
 void silc_packet_stream_destroy(SilcPacketStream stream);
 
+/****f* silccore/SilcPacketAPI/silc_packet_stream_is_valid
+ *
+ * SYNOPSIS
+ *
+ *    SilcBool silc_packet_stream_is_valid(SilcPacketStream stream);
+ *
+ * DESCRIPTION
+ *
+ *    Returns TRUE if the packet stream indicated by `stream' is valid and
+ *    has not been disconnected or destroyed.
+ *
+ ***/
+SilcBool silc_packet_stream_is_valid(SilcPacketStream stream);
+
 /****f* silccore/SilcPacketAPI/silc_packet_stream_set_router
  *
  * SYNOPSIS
@@ -590,7 +673,7 @@ SilcStream silc_packet_stream_get_stream(SilcPacketStream stream);
  *
  ***/
 SilcBool silc_packet_stream_link(SilcPacketStream stream,
-                                SilcPacketCallbacks *callbacks,
+                                const SilcPacketCallbacks *callbacks,
                                 void *callback_context,
                                 int priority, ...);
 
@@ -610,7 +693,7 @@ SilcBool silc_packet_stream_link(SilcPacketStream stream,
  *
  ***/
 void silc_packet_stream_unlink(SilcPacketStream stream,
-                              SilcPacketCallbacks *callbacks,
+                              const SilcPacketCallbacks *callbacks,
                               void *callback_context);
 
 /****f* silccore/SilcPacketAPI/SilcPacketWrapCoder
@@ -624,18 +707,26 @@ void silc_packet_stream_unlink(SilcPacketStream stream,
  *
  * DESCRIPTION
  *
- *    The encoder/decoder callback for silc_packet_stream_wrap.  If the
- *    `status' is SILC_STREAM_CAN_WRITE then additional data can be added
- *    to `buffer'.  It is added before the data that is written with
- *    silc_stream_write.  The silc_buffer_enlarge should be called to verify
- *    there is enough room in `buffer' before adding data to it.  The `buffer'
- *    must not be freed.
+ *    The encoder/decoder callback for silc_packet_stream_wrap.
  *
- *    If the `status' is SILC_STREAM_CAN_READ then data from the `buffer'
- *    may be read before it is passed to readed when silc_stream_read is
- *    called.  The `buffer' may be advanced also to hide data in it.
+ *    If the `status' is SILC_STREAM_CAN_WRITE then additional data can
+ *    be added to `buffer' which contains the data that is being written
+ *    to the stream.  There is at least 16 bytes of free space in head
+ *    space of the buffer in case new headers need to be added. 
+ *    The silc_buffer_enlarge should be called to verify that there is
+ *    enough room before adding data to it.  The `buffer' must not be freed.
+ *    If the return value is FALSE the encoding failed and the packet is
+ *    not sent at all and the stream will receive error.  Return TRUE if
+ *    the encoding succeeded.
  *
- *    This function returns FALSE in case of error.
+ *    If the `status' is SILC_STREAM_CAN_READ then data from the `buffer'
+ *    may be read before it is passed to reader when silc_stream_read is
+ *    called.  The `buffer' may be advanced also to hide data in it.  If
+ *    return value is FALSE the decoding failed (or the packet is ignored)
+ *    and the packet will not be processed by the wrapped packet stream.
+ *    If there are other packet streams wanting the same packet, they will
+ *    get it, and if not the packet will drop.  Return TRUE if decoding
+ *    succeeded.
  *
  ***/
 typedef SilcBool (*SilcPacketWrapCoder)(SilcStream stream,
@@ -651,6 +742,8 @@ typedef SilcBool (*SilcPacketWrapCoder)(SilcStream stream,
  *                                       SilcPacketType type,
  *                                       SilcPacketFlags flags,
  *                                       SilcBool blocking_mode,
+ *                                       SilcIdType src_id_type, void *src_id,
+ *                                       SilcIdType dst_id_type, void *dst_id,
  *                                       SilcPacketWrapCoder coder,
  *                                       void *context);
  *
@@ -677,6 +770,10 @@ typedef SilcBool (*SilcPacketWrapCoder)(SilcStream stream,
  *    once returns one complete SILC packet data payload (which is of type of
  *    `type').
  *
+ *    If src_id and/or dst_id are set they will be used as the ids in the
+ *    sent SILC packets.  If the dst_id is set then the stream will receive
+ *    packets only originating from that id.
+ *
  *    The `coder' is optional encoder/decoder callback which the packet engine
  *    will call if it is non-NULL.  It can be used to encode additional data
  *    into each packet when silc_stream_write is called or decode data before
@@ -692,6 +789,8 @@ SilcStream silc_packet_stream_wrap(SilcPacketStream stream,
                                   SilcPacketType type,
                                   SilcPacketFlags flags,
                                   SilcBool blocking_mode,
+                                  SilcIdType src_id_type, void *src_id,
+                                  SilcIdType dst_id_type, void *dst_id,
                                   SilcPacketWrapCoder coder,
                                   void *context);
 
@@ -859,7 +958,7 @@ SilcBool silc_packet_get_keys(SilcPacketStream stream,
  *
  * DESCRIPTION
  *
- *    Set the source ID and destinaion ID to be used when sending packets to
+ *    Set the source ID and destination ID to be used when sending packets to
  *    this packet stream.  The IDs to be used for a packet stream can be
  *    overridden when sending packets.  However, if the IDs do not ever change
  *    for the packet stream it is recommended they are set using this function.
@@ -871,6 +970,25 @@ SilcBool silc_packet_set_ids(SilcPacketStream stream,
                             SilcIdType src_id_type, const void *src_id,
                             SilcIdType dst_id_type, const void *dst_id);
 
+/****f* silccore/SilcPacketAPI/silc_packet_get_ids
+ *
+ * SYNOPSIS
+ *
+ *    SilcBool silc_packet_get_ids(SilcPacketStream stream,
+ *                                 SilcBool *src_id_set, SilcID *src_id,
+ *                                 SilcBool *dst_id_set, SilcID *dst_id);
+ *
+ * DESCRIPTION
+ *
+ *    Returns source and destination IDs from the packet stream.  The
+ *    `src_id_set' is set to TRUE if the source ID was returned.  The
+ *    `dst_id_set' is set to TRUE if the destination ID was returned.
+ *
+ ***/
+SilcBool silc_packet_get_ids(SilcPacketStream stream,
+                            SilcBool *src_id_set, SilcID *src_id,
+                            SilcBool *dst_id_set, SilcID *dst_id);
+
 /****f* silccore/SilcPacketAPI/silc_packet_set_sid
  *
  * SYNOPSIS
@@ -1002,23 +1120,30 @@ SilcBool silc_packet_send_va_ext(SilcPacketStream stream,
                                 SilcIdType dst_id_type, void *dst_id,
                                 SilcCipher cipher, SilcHmac hmac, ...);
 
-/****f* silccore/SilcPacketAPI/silc_packet_wait
+/****f* silccore/SilcPacketAPI/silc_packet_wait_init
  *
  * SYNOPSIS
  *
- *    void *silc_packet_wait_init(SilcPacketStream stream, ...);
+ *    void *silc_packet_wait_init(SilcPacketStream stream,
+ *                                const SilcID *source_id, ...);
  *
  * DESCRIPTION
  *
  *    Initializes a packet waiter for the packet stream `stream' and
  *    for the variable argument list of packet types.  The function
  *    silc_packet_wait can be used to block the thread until a packet
- *    has been received.  This function is used to initialize the waiting
- *    and to give the list of packet types that caller wish to receive.
- *    The variable argument list must end with -1.  To receive all
- *    packets use SILC_PACKET_ANY.  Returns a context that must be given
- *    to the silc_packet_wait function as argument.  Returns NULL on
- *    error.  To uninitialize the waiting call silc_packet_wait_uninit.
+ *    has been received.
+ *
+ *    This function is used to initialize the waiting and to give the list
+ *    of packet types that caller wish to receive.  The variable argument
+ *    list must end with -1.  To receive all packets use SILC_PACKET_ANY.
+ *    If the `source_id' is non-NULL then only packets of the specified
+ *    type from the specified `source_id' are received.  If it is NULL
+ *    then the packet source is ignored.
+ *
+ *    Returns a context that must be given to the silc_packet_wait function
+ *    as argument.  Returns NULL on error.  To uninitialize the waiting
+ *    call silc_packet_wait_uninit.
  *
  * NOTES
  *
@@ -1030,12 +1155,12 @@ SilcBool silc_packet_send_va_ext(SilcPacketStream stream,
  *    void *waiter;
  *
  *    // Will wait for private message packets
- *    waiter = silc_packet_wait_init(stream,
+ *    waiter = silc_packet_wait_init(stream, NULL,
  *                                   SILC_PACKET_PRIVATE_MESSAGE, -1);
  *
- *
  ***/
-void *silc_packet_wait_init(SilcPacketStream stream, ...);
+void *silc_packet_wait_init(SilcPacketStream stream,
+                           const SilcID *source_id, ...);
 
 /****f* silccore/SilcPacketAPI/silc_packet_wait_uninit
  *